Journal of African Earth Sciences xxx (2015) xxx–xxx Contents lists available at ScienceDirect Journal of African Earth Sciences journal homepage: www.elsevier.com/locate/jafrearsci Cenomanian–Turonian rudist (bivalvia) lithosomes from NW of Jordan ⇑ Sacit Özer a, , Fayez Ahmad b a Dokuz Eylul University, Engineering Faculty, Geological Engineering Department, 35160 Buca Campus, Izmir,_ Turkey b The Hashemite University, Faculty of Natural Resources and Environment, Department of Earth and Environmental Sciences, P.O. Box 150459, 13115 Zarqa, Jordan article info abstract Article history: Two rudist lithosomes characterized by high abundance but low in diversity are described from five mea- Received 29 December 2014 sured-stratigraphic sections in the Upper Cretaceous Hummar and Wadi As Sir Limestone Formations in Received in revised form 17 March 2015 the Ajlun and Kitim areas, in NW Jordan. The caprinid lithosome from the Hummar Formation is Accepted 19 March 2015 characterized by abundant occurrences of canaliculate rudists such as Caprinula boissyi d’Orbigny, Available online xxxx 1840, Neocaprina nanosi Plenicˇar, 1961, Caprina sp. (aff. schiosensis Boehm, 1892), but rare specimens of radiolitids such as Sauvagesia sharpei (Bayle, 1857), Sauvagesia/Durania sp. and Eoradiolites sp., along Keywords: with requienids (Apricardia sp.), indicating a late Cenomanian age. The hippuritid lithosome is deter- Rudists mined from the stratigraphically higher Wadi As Sir Limestone Formation and it is represented by Lithosomes Upper Cenomanian well-preserved specimens of Hippurites resectus Defrance, 1821 and also some specimens of Vaccinites Upper Turonian rousseli Douvillé, 1894 and Durania arnaudi (Choffat, 1891) indicating a late Turonian age. Palaeobiogeography The palaeobiogeography of determined rudists is compared with those of the carbonate platforms on Jordan northern and southern side of the Mediterranean Tethys. The presence of a depositional hiatus (or erosional unconformity) represented by the sharp boundary, karstic features, reworked carbonate lithoclasts and rudist fragments between Hummar and Wadi As Sir Limestone formations is also outlined. Ó 2015 Elsevier Ltd. All rights reserved. 1. Introduction upper Cenomanian and upper Turonian limestones of Hummar Formation and Wadi As Sir Limestone Formation, respectively Previous studies suggest that during the Late Cretaceous Jordan (Fig. 1). The boundary between these two formations is discussed was a part of the Levant platform on the northern part of the according to new stratigraphic data. The biogeographic Arabian Plate, where the shallow marine rudist-bearing limestones distribution of determined species is also emphasized. and dolomitic limestones were largely deposited on the Jordanian carbonate shelf during the Cenomanian and Turonian (Abed, 1982; Powell, 1989; Makhlouf et al., 1996; Alsharhan and Nairn, 1997; 2. Material and method Philip et al., 2000; Stampfli et al., 2001; Kuss et al., 2003; Schulze et al., 2003, 2004, 2005; Baaske, 2005; Powell and Moh’d, 2011). This study is based on the rudist specimens were collected from Despite is earlier work, except for the study based on some the following five measured stratigraphic sections in the area rudist determinations of Bandel and Mustafa (1996) from the between the Ajlun city and Kitim town in the NW of Jordan Ishtafina area (close to Ajlun city) in the NW of Jordan, there are (Figs. 1–6): no detailed studies on the rudist associations in Jordan. The study 1-Ishtafina section (Fig. 2): NW of Ajlun city, S of Ishtafina town of Bandel and Mustafa (1996) concerns some rudists of at latitude (32°21 24.699N) and longitude (35°44 16.884E). Cenomanian and Turonian age, and contains some stratigraphic 2-An Nuaymah section (Fig. 3): 1 km SE of An Nuaymah town at and palaeontologic problems as discussed, below, in the rudist latitude (32°23 20.717N) and longitude (35°51 04.663E). lithosomes section. 3-Samta section (Fig. 4): Between Ajlun city and Kitim town, The aim of this study is to present the rudist lithosomes from 3 km SE of Rihaba town at latitude (32°24 09.731N) and longitude the NW of Jordan based on the material recently collected from (35°48 26.204E). 4-Rihaba section (Fig. 5): 1 km SW of Rihaba town at latitude (32°24 34.862N) and longitude (35°48 46.700E). ⇑ Corresponding author. Tel.: +90 0 232 3017315; fax: +90 0 232 4531129. 5-Kitim section (Fig. 6): 1 km S of Kitim town at latitude (32°25 E-mail address: [email protected] (S. Özer). 56.400N) and longitude (35°51 01.127E). http://dx.doi.org/10.1016/j.jafrearsci.2015.03.013 1464-343X/Ó 2015 Elsevier Ltd. All rights reserved. Please cite this article in press as: Özer, S., Ahmad, F. Cenomanian–Turonian rudist (bivalvia) lithosomes from NW of Jordan. J. Afr. Earth Sci. (2015), http:// dx.doi.org/10.1016/j.jafrearsci.2015.03.013 2 S. Özer, F. Ahmad / Journal of African Earth Sciences xxx (2015) xxx–xxx Fig. 1. Location map of the studied area (inset top left) and geological map (modified from Abu Qudaira, 2005) showing the measured-stratigraphic sections (red asterisks: 1.Ishtafina, 2. An Nuaymah, 3. Samta, 4. Rihaba, 5. Kitim). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.) The radiolitids are mostly embedded within the limestones, but limestones of the formation are mainly characterized by the many free specimens of the canaliculate rudists and hippuritids monospecific clusters of canaliculate rudists. However, the greater allowed us to prepare the transverse sections of the valves. abundance of canaliculate rudists are represented in the Ishtafina The rudist specimens are deposited in the first author’s collec- section than in the other sections. Gastropods are also represented tion in Dokuz Eylul University, Izmir,_ Turkey, and also in the in the Ishtafina section, but are characteristically present above the Hashemite University, Faculty of Natural Resources and levels of rudist-bearing limestones. The thickness of the formation Environment, Department of Earth and Environmental Sciences, varies from 8 m to 18 m. Jordan. The lower boundary of the Hummar Formation cannot be observed in the studied sections. But, it is directly overlain with a sharp contact by the Wadi As Sir Limestone Formation as 3. Stratigraphy observed in the Ishtafina, Samta and Kitim sections (Fig. 7A and B). This boundary is predominantly characterized by karstic struc- The Cretaceous succession of Jordan consists of three Groups, in tures covering by fine grained probably beachrock carbonates, ascending order, Kurnub sandstone (Berriaisan to Albian), Ajlun reworked carbonate lithoclasts and rudist fragments (Fig. 7C and (Cenomanian to Turonian) and Belga (Coniacian to Eocene) D). Although features such as palaeosols, caliche beds and iron (Quennell, 1951; Burdon, 1959; Masri, 1963; Bender, 1974; Abed, impregnations typically represents evidence for emergence, are 1982; Powell, 1989; Abdelhamid, 1995; Abu Qudaira, 2005). The not present, the features noted above and also the absence of Ajlun Group is composed of five formations in the north of siliciclastic-rich Shuayb Formation and any palaeontologic data Jordan, from bottom to top, the Naur (?upper Albian-lower showing the lower or middle Turonian indicate a hiatus (or an ero- Cenomanian), Fuheis (Cenomanian), Hummar (upper sional unconformity) between these two formations. The origin of Cenomanian), Shuayb (upper Cenomanian to lower Turonian) and this hiatus remains unclear, and needs a detailed study outside the Wadi As Sir Limestone formations (upper Turonian) (Wetzel and scope of this paper, but it just seems not to be a local phenomena Morton, 1959; Basha, 1978; Dilley, 1985). The formations of this to the study area. It may a result of platform drowning or Oceanic carbonate platform Group unconformably overlie siliciclastics of Anoxic Event (OAE) 2, which have been reported from the the Kurnub Sandstone Group, and is overlain unconformably by Cenomanian/Turonian boundary throughout Jordan (Powell, the chalk-chert-phosphorite association of the Belga Group 1989; Schulze et al., 2004; Wendler et al., 2009; Powell and (Quennell 1951; Powell 1989; Powell and Moh’d, 2011). The Moh’d, 2011; Bandel and Salameh, 2013). A subaerial unconfor- Kurnub Sandstone Group and Naur Formation not outcropped in mity also marked by a calcrete and paleokarstic horizon separating the study area (Fig. 1). the upper Cenomanian Hummar and Fuheis formations has been The rudists of present study were collected from the Hummar recently described from an area southeast of Amman (Abed et al., and Wadi As Sir Limestone formations of the Ajlun Group. 2013), shows the presence of a crisis during this time in Jordan. The rudist-bearing limestones and dolomitic limestones of The C/T crisis has been well-studied from the northern (e.g., Hummar Formation are observed in all sections, except Rihaba Philip and Airaud-Crumière, 1991; Drzewiecki and Simo, 1997; section (Fig. 5), but interbedded marls with ammonites are also Schlager, 1999; Callapez, 2008) and also southern Mediteranean observed at An Nuaymah section (Fig. 3). Rudist-bearing Tethys such as Israel (Lewy, 1989, 1990; Buchbinder et al., 2000; Please cite this article in press as: Özer, S., Ahmad, F. Cenomanian–Turonian rudist (bivalvia) lithosomes from NW of Jordan. J. Afr. Earth Sci. (2015), http:// dx.doi.org/10.1016/j.jafrearsci.2015.03.013 S. Özer, F. Ahmad / Journal of African Earth Sciences xxx (2015) xxx–xxx 3 Fig. 2. Ishtafina measured-stratigraphic section (see for location to Fig. 1) showing the distributions of the identified rudists. Legend. 1. Limestone, 2. Marl, 3. Caprinid, 4. Radiolitid, 5. Hippuritid, 6. Gastropod, 7. Chert, 8. Stylolith, 9. Subaerial unconformity/hiatus. Frank, 2010; Frank et al. 2010), Lebanon (Ferry et al., 2007), (1965) and massive limestone by Bender (1974). In the studied Sinai-Egypt (Saber et al., 2009; Bauer et al. 2001; Hannaa, 2011; area, between Ajlun and Kitim towns, it consists of well-bedded El-Sabbag et al., 2011) and northern-southern Tunisia (Abdallah, massive limestones, dolomitic limestones, dolomites and lime- 2003) indicating that it is related to a global phenomena.